Discuss all things tuning in this section. News, products, problems and results.
The matter of using a Lamda probe vs EGT probe came up recently and I'm interested in the pros and cons.
Lambda (or wideband) and EGT are literally 2 different type of probe for 2 different measurement, so what do you mean with matter of use?
The EGT measures the temperature of exhaust manifold, the lambda measures the AFR Ratio..
I suspect he's referring to tuning using just EGT sensor(s) or using an AFR sensor. What are the pro's and con's vs each method.
In my opinion all 2 sensor still absolutely a must have if you're tuning or Reflashing an ECU
Posted by Ben Silcock on July 10 regarding tuning using EGT....
"EGT sensors also respond quite slowly - Even the best have a response time of 150 ms or worse. If you want a true indication of how each cylinder is operating, individual cylinder lambda sensors are the best option."
When I asked for more info, I was advised to post here, hence the query. I know the difference between EGT probe info and Lambda probe information, but the question relates to Ben's original statement above, and that relates to tuning. I tune using EGT because I don't have a computer-controlled EFI and find it somewhat time consuming but reliable. The actual EGT reading is irrelevant as I am looking for peak EGT, 50 deg rich of peak and 50 deg lean of peak. The latter for power, the other for economy and cool CHTs. On another engine, same application, I use the Lamda wide-band probe to adjust the mixture ( again, not EFI) and it works fine. I'm interested in any comments.
EGT should be much cheaper than O2, both the electronics modules and the sensors that plug in to them. If you have a limited budget or an engine that kills sensors often, individual EGTs will be cheaper both in the short run and the long run.
The quicker response of O2 sensors might be useful for track tuning, ramp runs on the dyno, or chasing brief or intermittent behavior. For instance the O2 trace will show pretty clearly when a cylinder misfires but the EGT might not react quickly enough to see anything. As an exercise, try to intentionally build a lean or rich spot at a certain RPM and check how long it takes for the EGT sensor to show the change in temperature.
O2 sensors can't measure exhaust temperature, they can't even do a good job of guessing at exhaust temperature. If you want to check if your turbocharger or cat converter are experiencing dangerous temperatures an EGT sensor is the only way to go.